Camping and hiking are currently enjoying a surge in popularity. However, people now have enhanced expectations of comfort and convenience while camping, and a large demand exists for products providing both comfort and convenience. Further, there are many different ways in which people like to camp. Some carry their equipment to remote places and require light and easily packed equipment, while others camp alongside their vehicles and primarily require comfort. Sleeping is one activity that is hard to perform well without a minimal comfort level. The surface upon which a camper sleeps can be very important in determining the level of comfort. In order to isolate the sleeper from the hardness and irregularities of the ground, it has become the practice of many campers to use an air mattress, which is basically a thick flat rubber balloon that can be interposed between the sleeper's sleeping bag and the ground.
There may be certain problems associated with using a sleeping bag with a separate air mattress. As a sleeping person turns in his sleep, the bag, which may be made of nylon or some other somewhat slippery material, may tend to slide off of the air mattress, and no camper likes to wake up in his sleeping bag to find himself rolled off of his mat. Additionally, campers can rarely find a perfectly flat spot to put their sleeping bags and their ground mats, so they often slide off of their air mattresses. While a tradeoff between ultra-comfort and ultra-light construction has previously seemed inevitable in sleeping bag design, the current invention provides more comfort and reliability in a lightweight sleeping bag.
Two primary considerations for comfort are the sleeping bag's ability to retain heat and the sleeping bag's ability to firmly support the user, even though the sleeping bag may be placed on uneven ground. While air mattresses have been found to support the user well, regardless of imperfections in the ground, the large air pockets currently used allow convective currents to form, robbing heat from the mattress. Foam, goose down, synthetic fibers, and other insulation materials are merely a means to hold small pockets of air. If an air mattress can be made with small pockets of air instead of large pockets, convective currents will not be able to form and the air mattress will retain more heat.
Temperature ratings are created with the assumption that you are using a sleeping pad because when a user lies in a sleeping bag, the user is compressing the fill material, whether it is down or synthetic, and thus reducing the loft and insulating capabilities of the bag. A sleeping pad puts another couple inches of insulation between the user and the cold ground, increasing the thermal effectiveness of the bag.
Various proposals for sleeping bags that incorporate air mattresses are found in the art. U.S. Pat. No. 3,877,092 discloses a self-inflatable air mattress and sleeping bag that traps air inside an airtight jacket filled with foam. Means are included to manually increase the air pressure inside the foam-filled jacket.
Further, numerous sleeping bag designs have been utilized with a plurality of parallel and longitudinally extended air compartments along with various improvements over the prior art. Such devices may be found in U.S. Pat. Nos. 4,996,733; 5,528,779; 5,553,339; 5,740,565; and 5,974,608, all of which are incorporated by reference herein in their entireties.
While possibly effective for their intended purposes, none of the above proposals provide an air mattress that can effectively retain heat by reducing large air pockets, provide a comfortable place to sleep, are lightweight and not bulky, and can be easily packed. Instead, prior art designs typically use air mattresses with large air pockets or are completely filled with foam.
Therefore, it is desirable to have a sleeping bag with an integral air mattress that effectively retains heat, is comfortable, is lightweight and compact, can be easily packed, is convenient to use, and does not require an excessive volume of air to inflate.